This invention relates generally to devices operating in air or water, and more particularly, to devices that are essentially passively stable in hover, and in horizontal motion, i.e., self-stabilized against disturbances in any direction without need for active stabilizer mechanisms controlled by inertial or aerodynamic sensors through a general logic system, as in an autopilot.
Devices that can hover in air or water are needed for many military and commercial applications. Vertical axis propeller systems can normally provide the thrust required to support the weight of the device, but previous designs have proved to be naturally unstable, and have had to be stabilized by active stability systems controlled by inertial or aerodynamic sensors, as in autopilots. These autopilots usually incorporate motion sensors, such as accelerometers, gyroscopic sensors, complex electronic processing networks and mechanical actuators to provide the actions to create the necessary stabilizing moments.
There is need for a simple, passively stable, hovering device that eliminates the requirement for auxiliary, active stabilizer means, or autopilots, as referred to.